1. Field of the Invention
The present invention relates to a torque control wrench for both a left-hand thread and a right-hand thread, and more particularly, to a torque control wrench for both a left-hand thread and a right-hand thread, which can set a torque value matching the strength of a bolt to be tightened and, if a torque equal to or greater than the set torque value is applied to the bolt, can discontinue rotation of a socket that is tightening the bolt by means of a torque controller, thereby tightening the bolt with a precise torque.
2. Discussion of the Related Art
A torque wrench is a tool used to precisely apply a specific torque (i.e. rotational force) to a bolt and a nut.
A vehicle is typically an assembly of a large number of parts tightened with bolts. These bolts vary in strength levels and a strength level is marked on the head of each bolt.
As bolts differ in strength levels depending on their types, the bolts have different maximum torques with which they can be tightened. If a wrench tightens a bolt with a greater torque than the strength of the bolt can tolerate, the head of the bolt may be deformed or the thread of the bolt may be broken off. Accordingly, a torque wrench tightens a bolt with a specified torque according to the strength level of the bolt.
FIG. 9 illustrates a conventional torque wrench.
Referring to FIG. 9, the conventional torque wrench is a popular one used to tighten or loosen bolts in exchanging tires for a vehicle.
The conventional torque wrench includes a wrench unit 210 and a handle 220. The wrench unit 210 has a socket 213 formed at an end thereof, for tightening or loosening a bolt and a male thread 211 formed on an outer circumferential surface thereof. The handle 220 is provided, on an inner circumferential surface thereof, with a female thread 221 for being screwed onto the male thread 211.
The conventional torque wrench is configured so as to control a tightening torque on a bolt by adjusting the length of the handle 220 relative to the length of the wrench unit 210.
However, the torque control mechanism of the conventional torque wrench is not effective in tightening a bolt with a precise torque because a torque applied to the bolt depends on an operator.
Moreover, the operator may overtighten the bolt without noticing the fully tightened state of the bolt. Consequently, the bolt may be worn out.